Cooling water tower systems are usually fabricated of ferrous metal. A common problem is severe corrosion which results from water and air contact with the metal, especially in the case where the cooling water is brackish.
Chromate type inhibitors formerly used to reduce corrosion have been banned for use because of environmental impact problems. Consequently, there is a need for a new effective corrosion inhibitor system and, of course, for one which exhibits improved efficiency inhibiting corrosion and which employs materials free of deleterious environmental impact effects.
Inhibitors currently available to the art, for example, phosphate, phosphonate, molybdate, nitrite and zinc types and the like reduce carbon steel corrosion rates in brackish water to an amount on the order of 16 to 35 mills per year (mpy). This is a series rate and one hardly acceptable considering replacement and repair costs for cooling towers.